title: Atomic order and magnetization distribution in the half metallic and nearly half metallic C1(b) compounds NiMnSb and PdMnSb.
abstract: Polarized neutron diffraction has been used to study the magnetization distribution in two isostructural inter-metallic compounds NiMnSb and PdMnSb. Band structure calculations have predicted that whereas the former should be a half metallic ferromagnet the latter should not. Measurements made at 5 K on different crystals show that disorder can occur between the A (Mn) and B (Sb) sites in both alloys and in the case of NiMnSb, by partial occupation of the void D sites by Ni. In all the crystals most of the moment was found on the Mn atoms in the A sites; in NiMnSb it is due to spin only but in PdMnSb there is evidence for a significant orbital contribution (g = 2.22). The magnitudes of the moments associated with each atom are in fair agreement with the theoretical values; however, the distribution of magnetization around the Mn atoms is found to have nearly spherical symmetry (40% e(g)) rather than the 50% e(g) character expected from the band structure.
authors.affiliation: Department of Physics, Loughborough University, LE11 3TU, UK. Institut Laue Langevin, BP 156, 38042 Grenoble, France.
authors.forename: P J
authors.initials: PJ
authors.lastname: Brown
authors.forename: A P
authors.initials: AP
authors.lastname: Gandy
authors.forename: R
authors.initials: R
authors.lastname: Kainuma
authors.forename: T
authors.initials: T
authors.lastname: Kanomata
authors.forename: T
authors.initials: T
authors.lastname: Miyamoto
authors.forename: M
authors.initials: M
authors.lastname: Nagasako
authors.forename: K U
authors.initials: KU
authors.lastname: Neumann
authors.forename: A
authors.initials: A
authors.lastname: Sheikh
authors.forename: K R A
authors.initials: KR
authors.lastname: Ziebeck